I know that the format can be dictated by the use of the file, but I was wondering what format others like/dislike to use and why as QCAD supports multiple formats. The DWG format is about 15% of the size of the DXF for the file on which I am working, so I will be inclined to use it for space savings.I'd like to know what others think.--Alex

Good topic. For me I use the dxf format more frequent than using DWG mainly because I can send dxf files directly to the laser cutters, quite often cnc driven devices will play better with dxf than dwg.

@andrew, hey just had an idea, how about a QCAD only file format option as well?

I also prefer the dxf file format because of it's plain text structure. Thus you can replace strings such as layer/block names in batch mode from the command line (or from a capable text editor). This is indeed very useful for me when developing satisfying layer names in multiple existing drawings .

After reading the article Husky posted and the other posts, I'd venture a guess that DXF is the best format to use. That is the format I have been using. I was just wondering as a few of my files have grown to more than a mega-byte in size, but as Husky pointed out, disk space is cheap and the internet is fast.